Heat spreaders are generally used in integrated circuit device packages. One such integrated circuit device package 100 is shown in the simplified schematic illustration of FIG. 1. The depicted package 100 is a ball grid array type package. In FIG. 1, there is a substrate 10 onto which an integrated circuit device (also referred to herein as an IC die or chip) 12 is mounted. The die 12 is commonly attached to a front side surface of the substrate 10. Commonly this means attachment to a front side die attach pad 11 with an epoxy material 13. The depicted substrate 10 includes copper conducting structures 11 (for example, bonding pads, bonding rings, bond fingers, and the like) that comprise electrical connections in the package 100. These wires 14 are connected to rows of bond pads on the die by ball bonds 15. Thus, the electrical connections of the die 12 are electrically connected to selected conducting structures 11 using the bonding wires 14. The die 12 is encapsulated with a molding material 17. Additionally, a heat spreader 18 is adhered (commonly using epoxy) to the front side surface of the substrate 10 to protect the die 12 and to spread the heat generated by the die 12 over a larger area. Importantly, in conventional packages the heat spreader 18 is attached to the top of the package. Thus, heat generated by the die 12 passes through the encapsulating layer 17 to thermally communicate with the heat spreader 18.
In many conventional applications such an arrangement has proved satisfactory. However, with the increasing circuit density within dies 12 arises a need for more connections from the die 12 to the substrate 10. The depicted configuration uses two rows 1,2 of die mounted bond pads to connect with the various conducting structures 11 of the substrate 12. It is becoming common to use three row implementations and newer packages will use four or more rows. With each added row comes the necessity to increase the height h of the layer of encapsulating molding material 17 to sufficiently protect the wires 14. As this height h increases the heat dissipation effectiveness of the heatspreader 18 decreases due to increasing distance away from the die. Additionally, as the processing power of modern semiconductor devices increases, such devices can perform more operations per second. With this increasing speed comes increasing heat. Thus, among other things, there is a need for systems and methods that can improve the thermal performance of the package. semiconductor package and methods for its fabrication are disclosed.
In general, the present invention is directed toward systems, packages, and methods for providing improved cooling in such packages and systems.
One embodiment of the invention comprises a semiconductor integrated circuit (IC) package. The package includes a packaging substrate with a heat spreader mounted on a first side of the substrate. An integrated circuit die is mounted to the heat spreader such that the die is in thermal communication with the heat spreader and such that the heat spreader lies in between the die and the substrate.
In another embodiment, a heat spreader plate for use in a semiconductor package is disclosed. The heat spreader plate comprises a plate comprised of thermally conductive material suitable for attachment to a packaging substrate. The plate includes openings configured to expose electrical bonding surfaces of a packaging substrate when the heat spreader plate is mounted on the packaging substrate. Such openings enable wirebonding between the exposed electrical bonding surfaces of the substrate and a integrated circuit die.
Other aspects and advantages of the invention will become apparent from the following detailed description and accompanying drawings which illustrate, by way of example, aspects of the invention.